If I compare the truss layout and design software used in the early 1980s to what is available today, it’s mind boggling. Actually, comparing layout software wouldn’t be possible since the first layout software at our company didn’t show up until around 1989! Up to that point, layouts were done with a pencil and paper, usually on ¼” grid graph paper to make life a little easier. Of course, every truss dimension – heel height, pitch, span, bearing location – was calculated by hand. In my case, I had my trusty Hewlett Packard HP15 scientific calculator always at the ready. I touched on this same subject in my September column, Design: Software Power or Brain Power?, but now rather than continuing to look back, I’d like to look forward.
The promise of BIM (building information modeling) for the truss and wall panel world would suggest that the plans we receive – or more accurately the 3D models – would include not only complete information with which to do our work but also fully accurate information.
Imagine these dreams as realities. No more interior walls dimensioned as 4” thick when they’re actually built from 2x4 with ½” sheetrock each side totaling 4½” in the real world. No more guessing about cladding dimensions when trying to determine the offset from bearing wall to finished cladding. And, perhaps best of all, no more looking at a cross section on a plan and wishing that the architect had taken the section just a couple of feet over so that it actually gave some idea of what the ceiling profile is supposed to be. (As a side note, I have jokingly told many architects that I secretly believe they take a course in how to provide cross sections with as little useful information as possible. I know that in many cases it is because the tools they are using aren’t necessarily up to the task either.)
But, when will these fully accurate BIM models begin to become common? Like flying cars, they always seem to be 5–10 years away – at least in the single family home construction sphere. Will builders and developers ever be willing to invest in the additional up-front costs to have full BIM models prepared, even if they do accept that there are cost savings available to them through construction efficiencies and catching problems early in the process? In the case of one-off custom homes, there is no opportunity to amortize any additional architectural costs over multiple builds, so savings have to be real and substantive on the first build. And, yes I do understand that in the BIM “world” collections of parts, assemblies, and tools promise to make plan preparation faster, but anecdotally I have been told that this is not yet the case.
Until such time as we can have a high degree of confidence in the BIM model we’re receiving, we’ll need truss, wall panel, and EWP designers that can read and interpret architectural drawings to understand intent. Add to that the need for designers to be able to comfortably communicate with builders, architects, and engineers so they can fill in the holes of missing information by asking productive questions. There is a real danger during the in-between period when BIM models are common but not yet fully reliable.
Yes, I do believe that there will come a time when BIM will ultimately fulfill its promise of streamlining the component design process, and more broadly construction as a whole. When that happens, there will be another wholesale shift in the component world, much like the shift from pencil and paper to 3D layout software. I just think that, when it happens, I’ll be out for a cruise in my fancy new flying car.
Do you agree? When do you think we’ll have fully deployed BIM? Whether you’re optimistic or pessimistic, please reach out, I’d love to hear from you.